Friday, March 20, 2009

Your eyes see one thing, your mind believes another!

Your eyes see one thing, your mind believes another!

Welcome our guest blogger Stefan Van den Bergh, who runs the "Planet Perplex" website. He writes: "I've been fascinated by illusions and everything like it for as long as I remember. Over the years I've made several sites about them, and built an extensive collection." It's been long since we had an article about optical illusions, so it's time for another installment in this highly popular series.

These don't move

Akiyoshi Kitaoka is a famous creator of moving illusions. That is, they seem to move but they don't.

Warning : these illusions are so strong that sensitive observers might feel sick. You will understand when you see them full-screen.

The first example is probably the most famous of them all and a favorite in poster stores: Rotating Snakes ! Make sure you click to enlarge.

When watching this picture, you might want to check if your flatscreen is still flat. Maybe it actually IS rippling.

These rotating ladybugs are rather unknown but extremely convincing. You just can't believe this is not an animation. (Watch fullscreen, bigger is better.)

The last not-quite-moving one is also a classic but too good to leave it out. Stare at the black dot and move your head back and forth from the screen. The wheels will start turning ...

These do move - in strange ways

This little animation is fast becoming very popular - and no wonder: when you first look at the spinning girl, her rotation is probably clockwise. But if you start to concentrate on her shadow instead, suddenly her rotation switches to counter-clockwise! It may take some time, but the moment it happens, you are going to be genuinely surprised... (first seen here)

This ferris wheel animation is similar to the one above. Look at the left side of the wheel, and it will rotate to the left. Look at the right and it will rotate there. If you play around with it, you can make it turn wherever you want. Try it!

Unique Stereo Pictures can be created using a simple animation effect. This pool animation has only two frames, but looks convincingly three-dimensional.

Have a look at this photograph of Neuchatel, Switzerland. How long would it have taken Felice Varini to put the red lines there ? Five minutes, with a pencil and a ruler ?

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I don't know exactly but it would have been much, much longer. You see, the red lines are actually painted on the buildings. He just took buckets of red paint and got into town, as you will see below. This illusion only works from one exact point of view.

Here are some more examples of his work (there are dozens more at his site)

Another superb example of Varini's 3-D work is the Cardiff's Harbor, where the whole site became a "canvas" for Felice Varini's shapes, which could be discovered only from a specific viewpoint...

3-D Transformations

Shigeo Fukuda is another great point-of-view artist, "Master of Transformations". See for example his "Underground Piano". It looks like a large pile of junk, but when seen in a mirror just right, it's a perfect image of a piano.

Here is "Encore" sculpture, which changes into different musicians, depending on your point-of-view. (via Growabrain)

Shadow Sculptures

Again, by Shigeo Fukuda - watch this video to see the shadows transform a pile of junk.

Our illusions coverage will be incomplete if we don't mention other "shadow sculptures" - see a superb page here

But point-of-view illusions can also happen just by accident. And when they do, the result can be hilarious ...

For an interesting case of "cover-up" viewing-angle illusion (and a study of Medieval morals) see this page

Now you see it ...

Now a bit of magic - let's make some stuff disappear. The first illusion is a classic, but keeps baffling me every time. Stare at the black cross in the center. Within seconds, a green ball will appear. And a few seconds after that, the green ball starts eating the purple balls, until there's nothing left !

This one has no moving parts. Just look at the black cross and see the colored fluff fade away until everything is gray. See how easy your eyes are fooled ?

Speaking about elusive color... This link is simply mind-boggling. Follow the instructions to see the color appear out of black-n-white image of the castle. Click here

Adding to more well known images (see our first part), here is a variation of "shading illusion" - these two cubes are the SAME color!

Hi! I represent Darlyne Murawski, and we'd appreciate it if you could take down the image of the Hawaiian Happy Faced Spider. There are two problems with its use on the blog. First, in spite of the note stating the image was used "courtesy Darlyne Murawski", we never received any request to use the photograph. Second, although you suggest that the image isn't a photoshop job, it has been altered from the original. As a professional photographer, Darlyne gets pretty touchy about modifications that mis-represent her work. If you'd like to keep the spider in this post, you could link to the image on Darlyne's website: http://darlynemurawski.com/galleries/spiders/page1.php